Backdrive assemblies are used to return a mechanism connected to the assembly back to an initial position after being actuated. For example, a backdrive assembly may be used with a motor shaft, gear trains, or levers such as, for example, a vehicle door latch. The backdrive assembly includes a torsion spring that may be connected to and rotates, for example, a gear that back drives a complementary nut attached thereto by exerting a proportional and opposite twisting force to the gear. Convention backdrive assemblies that use torsion springs are not easy to assemble into the gear and/or the nut with a pre-load. These springs are assembled with the mechanism and must be twisted to create a specific torsion load. These springs may lose their pre-winding loads after removal of the assembly fixture from the mechanism. Typical issues include the springs popping up from the gear/nut, losing turns, or legs of the torsion spring disconnecting from the gear and/or nut.
Accordingly, it is desirable to provide a backdrive arrangement with a variable bias preload during manufacturing of the system. More specifically, it is desirable to provide a backdrive arrangement that employs a variable preload feature for retaining the backdrive biasing member to the assembly at a defined preload while at a rest position.